Microencapsulation involves the packaging of small particles of solid, liquid or gas within a secondary material to form a microcapsule. It has been used for targeted delivery of drugs in the body in the pharmaceutical industry. It is increasingly being seen as a technology that offers novel food processing solutions. With the use of microencapsulation, possible undesirable interactions between the added nutraceutical and other components in the food or its environment can be avoided and the site of release of the added component can be manipulated. The appropriate application of microencapsulation technology enables the fortification of food without affecting the taste, aroma or texture of food. It can afford protection to sensitive food ingredients and enhance the shelf-life and stability of fortified foods (Brazel, C. S. (1999) Microencapsulation: offering solutions for the food industry. Cereal Foods World 44(6): 388-393; Augustin, M. A., Sanguansri, L., Margetts, C. and Young. B. (2001) Microencapsulation of food ingredients. Food Australia 53 220-223).
Microencapsulation can serve both the purposes of the food and health industries, as it is a key technology with potential for the delivery of dietary bioactives and development of successful marketable functional foods. Addressing this challenge, requires tailoring the performance of food grade microcapsules in a food processing environment so that essential sensitive components are protected during food manufacture and the microcapsules can also meet the need for site specific delivery within the gastrointestinal tract.
Directing nutraceuticals and therapeutics of the colon is of interest for treatment of colon diseases (Rubinstein, A., Tirosh, B., Baluom, M., Nassar, T., David, A., Radai, R., Gliko-Kabir, I. And Friedman, M. (1997). The rationale for peptide drug delivery to the colon and the potential for polymeric carriers as effective tools. J. Controlled Release 46, 59-73). Targeting to colon has been carried out by formation of pro-drugs which are enzymatically cleaved in the colon, and multi-coats with pH sensitive and pressure dependent release. Often enteric acrylic polymers are used to protect cores in colon-delivery formulations. Biopolymers, particularly polysaccharides, may be used for targeting cores to the colon where the release of cores is triggered by the microflora in the colon. A range of polysaccharides such as chitosan, pectin, arabinoxylan, arabinogalactan, xylan, cellulose dextrans, guar gum, amylose, inulin and mixtures of these have been examined and shown to have potential as colon-delivery systems (Rubinstein, A. (2000) Natural Polysaccharides as targeting tools of drugs to the human colon. Drug Development Research 50, 435-439; Sinha, V. R. and Kumaria, R. (2001) Polysaccharides in colon-specific drug delivery Int. J. Pharmceutics 224, 19-38; Vandaamme, Th. F., Lenourry, A., Charrueau, C. and Chaumeil, J.-C. (2002) The use of polysaccharides to target drugs to the colon. Carbohydrate Polymers 48, 219-231; Sinha, V. R. and Kumaria. R. (2003) Microbially triggered drug delivery to the colon. Eur. J. Pharmaceutical Sciences 18, 3-18).
There have been a number of attempts to use biopolymers for colon delivery and for treating colonic diseases
U.S. Pat. No. 5,952,314 discloses an enteral product comprising an oil blend with fatty acids {EPA (C20:5) and DHA (C22:6)} and a source of indigestible carbohydrate which is metabolised to short chain fatty acids in the colon. It has use for improving nutritional status and treating ulcerative colitis
U.S. Pat. No. 5,108,758 discloses a glassy amylose matrix for delivery of medication to the colon
U.S. Pat. No. 5,840,860 is concerned with delivery of short chain fatty acids (SCFA) to the colon by way of a modified starch.
Japanese patent 10324642 discloses a colon delivery system for delivery of bioactives (eg peptides) comprising inner layer of chitosan and outer-layer of gastric resistant material such as wheat gliadin or zein.
U.S. Pat. No. 5,866,619 discloses a colonic delivery system for drugs such as proteins and peptides comprising a saccharide containing polymer
U.S. Pat. No. 6,368,629 discloses a drug coated with an organic acid-soluble polymer and a saccharide for colon delivery.
U.S. Pat. No. 5,444,054 discloses a method of treating colitis with a composition containing oil blend (with DHA/EPA) and a source of indigestible carbohydrate (CHO) which is metabolised to short chain fatty acids.
U.S. Pat. No. 5,952,314 is concerned with an enteral nutritional product for treatment of colitis which comprises oil containing EPA/DHA and a source of indigestible carbohydrate which is metabolised to short chain fatty acids.
U.S. Pat. No. 6,531,152 describes a drug delivery system containing a water soluble core (Ca pectinate or other water-insoluble polymers) and outer coat which bursts (eg hydrophobic polymer—Eudragrit) for delivery of enterally-administered drugs to specific locations along the gastrointestinal tract
There are proposals using combinations of proteins and polysaccharides for the formation of coating systems.
U.S. Pat. No. 6,234,464 discloses a system in which oils/polyunsaturated fatty acids (PUFA)/fatty acids are provided with capsules comprised of two layers in which the inner layer consists of gelatin, casein or alginate and the outer layer consists of gelatin, gum arabic, chitosan to provide a product stable in boiling water
U.S. Pat. No. 6,403,130 discloses a coating composition comprising a polymer containing casein and high methoxy pectin (amide formed by reaction of ester group R′COOCH3 of pectin with free amino group of protein R″NH2)
WO 01/74175 discloses the encapsulation of oxygen sensitive materials such as polyunsaturated oils in a protein carbohydrate film treated to form a Maillard reaction product.
It is an object of this invention to provide a gastrointestinal delivery system that can be used with storage unstable ingredients as well as providing protection during delivery through the gut.